摘要The April 20, 2013 Lushan earthquake which occurred in Sichuan, China had only moderate thrust. However, the computed seismic moments (M0) for the Lushan earthquake calculated by several institutions differ significantly from 0.4×1019 to 1.69×1019 Nm, up to four times difference. We evaluate ten computed M0s by using normal mode observations from superconducting gravimeters in Mainland China. We compute synthetic normal modes on the basis of moment tensor solutions and fit them to the observed normal modes. Comparison of our results indicates that M0 is the main cause for some large differences between observations and synthetics. We suggest that a moment magnitude of Mw6.6, corresponding to a M0 of 0.97–1.08×1019 Nm, characterizes the size and strength of the seismic source of the Lushan earthquake.
Abstract：The April 20, 2013 Lushan earthquake which occurred in Sichuan, China had only moderate thrust. However, the computed seismic moments (M0) for the Lushan earthquake calculated by several institutions differ significantly from 0.4×1019 to 1.69×1019 Nm, up to four times difference. We evaluate ten computed M0s by using normal mode observations from superconducting gravimeters in Mainland China. We compute synthetic normal modes on the basis of moment tensor solutions and fit them to the observed normal modes. Comparison of our results indicates that M0 is the main cause for some large differences between observations and synthetics. We suggest that a moment magnitude of Mw6.6, corresponding to a M0 of 0.97–1.08×1019 Nm, characterizes the size and strength of the seismic source of the Lushan earthquake.
基金资助:National Natural Science Foundation of China (Nos. 41174022 and 41021003)
通讯作者:
Xiaogang Hu
E-mail: hxg432@whigg.ac.cn
引用本文:
Xiaogang Hu, Ying Jiang. Evaluation of the seismic moment of the April 20, 2013 Lushan earthquake[J]. 《地震学报》英文版, 2013, 26(3-4): 169-177.
Xiaogang Hu, Ying Jiang. Evaluation of the seismic moment of the April 20, 2013 Lushan earthquake. Earthquake Science, 2013, 26(3-4): 169-177.
